Anna Vizi-Orosz

Phosphido cobalt carbonyl clusters Pn[Co(CO)3]4−n (n = 1, 2, 3)☆

Abstract The Pn[Co(CO)3]4−n (n = 1, 2, 3) tetrahedral clusters have been prepared and characterized. The very unstable PCo3(CO)9 can be stabilized in the form of (CO)4FePCo3(CO)9

AsCo3(CO)9, its cyclic trimer, As3Co9(CO)24 and the phosphorus-containing analog P3Co9(CO)24☆

The AsCo3(CO)9 trigonal pyramidal cluster, its cyclic “trimer” As3Co9(CO)24 and the phosphorus-containing analog of the latter, P3Co9(CO)24 have been prepared and characterized. A reversible equilibrium between the arsenic-containing monomer and trimer was found to depend on p(CO). Such an equilibrium could not be observed in the case of P3Co9(CO)24.

Preparation and infrared spectra of monosubstituted PR3 and P(OR)3 (R alkyl, aryl) derivatives of (μ2-L)2Co2(CO)6 compounds☆

Abstract (μ 2 -L) 2 Co 2 (CO) 5 PR 3 and (μ 2 -L) 2 Co 2 (CO) 5 P(OR) 3 (R  alkyl, aryl, L 2  P 2 , As 2 , acetylene, L  CO and but-2-en-4-olid-4-ylidene) compounds were prepared. The ν(CO) infrared spectra are in agreement with the expected C s or C 1 symmetry. The results indicate that the PR 3 or P(OR) 3 substituent is in all cases in the axial position.

Transformations of the heteronuclear clusters En[Co(Co)3]4−n (E = P, As; n = 1–3) when treated with soft lewis acids and bases

Abstract The tetrahedral pnigogenic clusters E n [Co(CO) 3 ] 4 - n (EP, As; n = 1–3) react with soft Lewis acids and bases to give products of substitution and transformation of the cluster. Lewis acids promote transformations to clusters containing more cobalt atoms and Lewis basis to clusters containing fewer such atoms.

On the reactivity of μ2-acetylenes coordinated to cobalt : Stereochemistry of the formation of the butene-2-olide-4 complexes: Co2(CO)7(RR′C4O2)

Abstract The relative positions of the R and R′ substituents in the “lactone” complexes, Co2(CO)7(RR′C4O2) (μ2-carbonyl-μ2-spiro-[2,3-substituted-2-butene-4- olide-4-ylidene]-bis[tricarbonylcobalt][CoCo] derivatives) was studied spectroscopically. It was found that the formation of these complexes is stereoselective and is controlled by the bulk of the substituents R and R′.

Phosphido cobalt carbonyl cluster: Co2(CO)6P2 and Co3(CO)9 PS

Abstract Two phosphido cobalt carbonyl cluster Co(CO)6P2 and Co3(CO)9PS have been prepared and characterised.

Reaction of coordinated diphosphorous with metal carbonyl fragments. Crystal structure of [(CO)5Cr][(CO)5W]P2Co2(CO)6

Abstract Either one or two of the metal carbonyl fragments Cr(CO)5, Mo(CO)5, W(CO)5 or Fe(CO)4 can become linked to the coordinated diphosphorous molecule of (μ2-P2)Co2(CO)5L (L = CO, PBu3, PPh3) when the latter species is treated with THF adducts of these fragments. The structure of [(CO)5Cr][(CO)5W]P2Co2(CO)6 has been determined by X-ray diffraction.

Mono- or polynuclear surface species: Models and tendencies with cobalt and rhodium

Abstract Models of surface reactions of cobalt and rhodium carbonyls with oxide or thiolate type supports were prepared and characterized. For Co carbonyls it was found that simple noncarbonyl ligands that can be formed in reductive CO reactions may promote clusterification under conditions where the support alone causes declusterification. Model complexes of the interaction of rhodium with silica and aromatic thiolate supports were structurally characterized by X-ray diffraction. Model compounds indicate that organic thiolate supports promote clusterification with cobalt and declusterification with rhodium.

Electronic effects and the infrared spectra of μ2-alkynehexacarbonyldicobalt compounds☆

The influence of the electronic structure of R and R′ in species of general formula (RC2R′)Co2(CO)6 on their infrared spectra in the v(CO) region provides independent evidence for the assignment of the carbonyl stretching bands.

μ,μ,-bis(alcoholato)- and μ,μ-bis(phenolato)dirhodium(I) tetracarbonyl complexes

Abstract Rh2(CO)4(OR)2 complexes (R = Me, Et, Pr, i-pent, Ph, p-chlorophenyl) were prepared from Rh2(CO)4Cl2 and sodium alcoholates or phenolates. They are converted by phosphines into the monomeric Rh(CO)(PR′3)2(OR) derivatives (R′ = Bu, Ph) via Rh2(CO)3(PR′3)(OR)2 intermediates.